Fuji Xerox Co., Ltd.

Kazuo Yamasaki

Katsumi Daimon

Yasuo Sakaguchi

Fumiaki Tambo

Masakazu Iijima

Katsumi Nukada

Akira Imai

Kiyokazu Mashimo

Toru Ishii

Yasuhiro Yamaguchi

Ryosaku Igarashi

Michiaki Takahashi

Kenichi Kobayashi

Takayuki Yamada

Hiroyuki Hotta

Kazuhiro Koseki

Masayuki Nishikawa

Yoshiyuki Ono

Fumio Ojima

Masaki Yokoi

Hitoshi Kojima

Hydroxygallium phthalocyanine crystals and an electrophotographic photoreceptor comprising the same. The hydroxygallium phthalocyanine crystals contain at least one of a polar organic solvent selected from the group consisting of a compound having an amido group, a compound having a sulfoxide group, and an organic amine.

Hydroxygallium phthalocyanine crystals and electrophotographic

An excellent electrographic photosensitive member having a high sensitivity, a high chargeability and a low residual potential. The electrographic photosensitive member comprises a photosensitive layer, or a photosensitive layer and an underlayer superimposed over an electroconductive support, wherein the photosensitive layer and/or the underlayer contain a chlorogallium phthalocyanine which is substituted with an electron-withdrawing group and has the following formula: ##STR1## where X represents an electron-withdrawing group such as a halogen atom and n is an integer of 2 to 4.

Electrographic photosensitive member

Hydroxygallium phthalocyanine crystals having intense diffraction peaks at Bragg angles (2.theta..+-.0.2.degree.) of 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree. in Cuk.alpha. characteristic X-ray diffractometry, a process for producing the same, and an electrophotographic photoreceptor containing the same are disclosed. The hydroxygallium phthalocyanine crystals are obtained by once preparing impurity-free hydroxygallium phthalocyanine having intense X-ray diffraction peaks at specific Bragg angles, followed by a solvent treatment for crystal transformation, in which the impurity-free crystals are prepared by using excess phthalocyanine ring-forming compound in the synthesis of starting gallium phthalocyanine or by removing insoluble matter from the acid paste of starting gallium phthalocyanine.

Hydroxygallium phthalocyanine crystal, and electro-photographic

Hydroxygallium phthalocyanine crystals having intense diffraction peaks at Bragg angles (2.theta..+-.0.2.degree.) of 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree. in CuK.alpha. characteristic X-ray diffractometry, a process for producing the same, and an electrophotographic photoreceptor containing the same are disclosed. The hydroxygallium phthalocyanine crystals are obtained by once preparing impurity-free hydroxygallium phthalocyanine having intense X-ray diffraction peaks at specific Bragg angles, followed by a solvent treatment for crystal transformation, in which the impurity-free crystals are prepared by using excess phthalocyanine ring-forming compound in the synthesis of starting gallium phthalocyanine or by removing insoluble matter from the acid paste of starting gallium phthalocyanine.

Hydroxygallium phthalocyanine crystal, process for producing the same,

An electrophotographic photoreceptor comprising a conductive substrate having thereon at least a subbing layer comprising an organometallic compound (e.g., organozirconium or organotitanium compound) and 3 to 30% by weight, based on the organometallic compound, of a compatible binder resin, a charge generating layer prepared by using a coating composition comprising hydroxygallium phthalocyanine crystals (preferably those having a novel crystal form) as a charge generating material, a binder resin, and a halogenated benzene as a dispersing medium, and a charge transporting layer in this order. The photoreceptor is excellent in sensitivity and stability on repeated use and is free from coating defects.

Electrophotographic photoreceptor with subbing layer and charge

Crystals of hydroxygallium phthalocyanine, a method of preparing the crystals, a photoconductive material containing the crystals, and an electrophotographic photoreceptor having the material. The photoreceptor has excellent electrophotographic characteristics. The crystals of hydroxygallium phthalocyanine have distinct diffraction peaks at (i) 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree., or (ii) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree., or (iii) 7.9.degree., 16.5.degree., 24.4.degree. and 27.6.degree., or (iv) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 18.1.degree., 24.5.degree., 26.2.degree. and 27.1.degree., or (v) 6.8.degree., 12.8.degree., 15.8.degree. and 26.0.degree. or (vi) 7.4.degree., 9.9.degree., 25.0.degree., 26.0.degree., and 28.2.degree. of the Bragg angle (2.theta..+-.0.2) in the X-ray diffraction spectrum. The electrophotographic photoreceptor has a light-sensitive layer containing the photoconductive material of the crystals.

Electrophotographic photoreceptor

An electrophotographic photoreceptor comprising a conductive substrate having provided thereon a photoconductive layer is disclosed, said photoconductive layer containing a high polymeric compound comprising a repeating unit comprised of a tetracarboxylic acid anhydride skeleton and a divalent organic group skeleton having an aromatic nucleus, said two skeletons being bonded via a nitrogen atom. Said high polymeric compound is formed by co-deposition of a tetracarboxylic acid anhydride compound and an aromatic diamine compound. The photoreceptor exhibits high sensitivity, high durability, and excellent image quality retention even when used repeatedly or in a high humidity environment.

Electrophotographic photoreceptor comprising polyimide resin

Crystals of hydroxygallium phthalocyanine, a method of preparing the crystals, a photoconductive material containing the crystals, and an electrophotographic photoreceptor having the material. The photoreceptor has excellent electrophotographic characteristics. The crystals of hydroxygallium phthalocyanine have distinct diffraction peaks at (i) 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree., or (ii) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree., or (iii) 7.9.degree., 16.5.degree., 24.4.degree. and 27.6.degree., or (iv) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 8.1.degree., 24.5.degree., 26.2.degree. and 27.1.degree., or (v) 6.8.degree., 12.8.degree., 15.8.degree. and 26.0.degree. or (vi) 7.4.degree., 9.9.degree., 25.0.degree., 26.0.degree., and 28.2.degree. of the Bragg angle (2.theta..+-.0.2) in the X-ray diffraction spectrum. The electrophotographic photoreceptor has a light-sensitive layer containing the photoconductive material of the crystals.

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Minami-ashigara, Japan

Kazuo Yamasaki